FIG. 1 is a perspective view of an exemplary prior art optical proximity sensor 102 that includes a cover lid 122, which is shown as being removed. The sensor 102 includes a light source die 104 and a light detector die 106 spaced apart from on another and attached to a base substrate 108 (e.g., a printed circuit board (PCB)). The light source die 104 is encapsulated in a clear epoxy 114, and the light detector die 106 is separately encapsulated in a clear epoxy 116. There is a gap 112 between the clear epoxy 116 encasing the light detector die 106 and the clear epoxy 116 encasing the light source die 104, wherein the gap 112 accepts a crosstalk barrier 132 (that is part of the cover lid 122) when the cover lid 122 is attached to the substrate 108. The cover 122, which is likely made of metal, includes a window 124 for the light source die 104 and separate window 126 for the light detector die 126. The opaque crosstalk barrier 132 (integrally formed with or attached to the cover lid 122) is used to optically isolate the light source die 104 from the light detector die 106.
As can be appreciated from the exemplary prior art optical proximity sensor 102 described with reference to FIG. 1, current packaging of optical proximity sensors involve many components and many process steps, which increase the bill of materials, escalate manufacturing costs, increase cycle times, and incur high yield losses.